Express bin lift for automated storage system

ABSTRACT

A lift system for an automated storage system of the type where storage containers are stacked in storage columns arranged in a grid, and where automated container handling vehicles retrieve and replace containers from a top level of the grid. The lift system has a platform vertically movable adjacent to a face of the grid, arranged for receiving and transporting one or more containers. A dedicated mechanical device is arranged for grabbing, lifting and moving the storage containers from a staging area at the top of the grid and placing containers on the platform and vice versa.

TECHNICAL FIELD

The present invention relates to an automated storage and retrievalsystem for storage and retrieval of containers, in particular to a liftapparatus and system for moving containers between vertical levels of agrid storage system.

BACKGROUND AND PRIOR ART

Automated grid storage system generally:

FIG. 1 discloses a typical prior art automated storage and retrievalsystem of the type sold commercially by the present applicant. FIG. 1shows a framework structure 100 and FIGS. 2 and 3 disclose two differentprior art container handling vehicles 20L301 suitable for operating onsuch a system.

The framework structure 100 comprises a number of upright members 102and a number of horizontal members 103 which are supported by theupright members 102. The members 102, 103 may typically be made ofmetal, e.g., extruded aluminum profiles.

The framework structure 100 defines a storage grid 104 comprisingstorage columns 105 arranged in rows, in which storage columns 105storage containers 106, also known as bins, are stacked one on top ofanother to form stacks 107. The storage grid 104 guards againsthorizontal movement of the stacks 107 of storage containers 106, andguides vertical movement of the containers 106, but does normally nototherwise support the storage containers 106 when stacked.

The automated storage and retrieval system 1 comprises a rail system 108arranged in a grid pattern across the top of the storage grid 104, onwhich rail system 108 a plurality of automated container handlingvehicles 201,301 travel. The container handling vehicles have agripping/lifting mechanisms 202/302 used to grip, and then raise storagecontainers 106 from, or lower storage containers 106 into, the storagecolumns 105. In one embodiment shown in FIGS. 2 a and 2 b . thegripping/lifting mechanism 202 raises the containers into a cavity inthe body of the vehicle. FIGS. 3 a and 3 b show an alternativeconfiguration of a container handling vehicles 301 in which thegripping/lifting mechanism 302 is arranged as part of a cantileverconstruction 303. Such a vehicle is described in detail in e.g.,N0317366, the contents of which are also incorporated herein byreference.

The container handling vehicles are arranged to transport the storagecontainers 106 above the storage columns 105. The rail system 108comprises a first set of parallel rails 110 arranged to guide movementof the container handling vehicles 201,301 in a first direction X acrossthe top of the frame structure 100, and a second set of parallel rails111 arranged perpendicular to the first set of rails 110 to guidemovement of the container handling vehicles 201,301 in a seconddirection. Y which is perpendicular to the first direction X. In thisway, the rail system 108 defines grid columns 1 12 above which thecontainer handling vehicles 201,301 can move laterally in an X or Ydirection above the storage columns 105, i.e., in a plane which isparallel to the horizontal X-Y plane. The upper part of a column(105/112) in the horizontal plane, denoting the position of the columnin the grid in the two horizontal dimensions, may be referred to as a“cell”.

For monitoring and controlling the automated storage and retrievalsystem 1, e.g. monitoring and controlling the location of respectivestorage containers 106 within the grid 104, the content of each storagecontainer 106; and the movement of the container handling vehicles201,301 so that a desired storage container 106 can be delivered to thedesired location at the desired time without the container handlingvehicles 201,301 colliding with each other, the automated storage andretrieval system 1 comprises a control system which typically iscomputerized and which typically comprises a database for keeping trackof the storage containers 106.

Transport of containers to an access station or different levels in amulti-level grid system:

The containers in the grid system often must be moved from theirpositions in the columns to an access station (not shown), typicallylocated at a lower level of the grid, where an operator, either human orautomated, may remove items from the containers to be placed in ashipping container or the like, and/or restock a container forreplacement in the grid.

In a storage grid 104, a majority of the grid columns 112 are storagecolumns 105, i.e., columns where storage containers 106 are stored instacks 107. However, a grid 104 normally has at least one grid column112 devoid of storage containers 106, through which the containerhandling vehicles 201,301, using their own lifting mechanisms, can raiseor lower storage containers 106 to a different level. Within the art,such a grid column is referred to as a ‘port column’ 1 19,120 and thelocation at the top or bottom of the column is normally referred to as a‘port’. According to one aspect, a conveyor belt system may be arrangedbelow the port column, onto which the container handling vehicles lowerthe containers for further transport to and from the access station. Insome instances, a grid has one or more port columns dedicated tolowering containers for delivery, and different port columns dedicatedto lifting containers for retrieval.

In other instances, a grid storage system comprises a plurality ofvertically arranged levels or sections, each with its own top level andcontainer handling vehicles. In such a multi-level system it is oftendesirable to move a container from one level to another. This also isperformed by a container handling vehicle lowering or raising acontainer from one level to another through a port column.

WO/2014/075937 describes a storage system with a dedicated bin liftarrangement for vertically transporting storage bins to a deliverystation or different levels of a multi-level storage system. The liftarrangement is arranged to transport bins through one or more individualport columns.

Disadvantages with the prior art:

There are a number of disadvantages to using the lifting mechanism ofthe container handling vehicles themselves to vertically move containersthrough a port column.

One disadvantage is that the prior art system requires very preciseconstruction and maintenance of the framework structure in order for theport columns to be properly aligned. This is particularly true in amulti-level system, where the various levels must be painstakinglyaligned with each other in order for a container passing through a portcolumn of one level to properly meet a column of a different level.Misalignment of the framework may also result in vehicle collisions. Anyfuture settling or shifting of the framework (for example due totemperature differences) can cause port columns to become misalignedthus disrupting the, delivery of containers.

Another disadvantage is that the speed and robustness of the liftingmechanism of the container handling vehicles is necessarily limited dueto considerations of size and expense of the vehicles. This reduces thethroughput capacity of the automated storage system.

A further disadvantage is that congestion may occur in the vicinity of aport, as vehicles wait for other vehicles to vacate the space above theport columns. This also negatively impacts the throughput capacity ofthe automated storage system.

SUMMARY OF THE INVENTION

The invention has been defined in the patent claims.

More specifically, the invention provides a storage system as set forthin the introduction, which further comprises a platform verticallymovable adjacent to a face of the grid, arranged for receiving andtransporting one or more containers. A dedicated mechanical device isarranged for grabbing, lifting and moving the storage containers fromthe top of the grid and placing containers on the platform and viceversa.

In one embodiment, the dedicated mechanical device is a manipulatortrolley arranged to travel along two parallel trolley rails, saidtrolley rails extending from a position above the grid to a positionabove the platform wherein the area between the trolley rails defines astaging area comprising a plurality of cells arranged to receive storagebins awaiting retrieval by the manipulator trolley and/or to receivestorage bins awaiting retrieval by the handling vehicles.

The storage system may comprise multiple vertically arranged levels,each of the grids being provided with its own manipulator trolley. Inthis arrangement the platform in one embodiment is movable in ahorizontal direction in an amount sufficient to compensate for anyhorizontal misalignment between the grids, such that containerstransported from one level may be retrieved by a manipulator trolley ona different level.

According to another aspect, the invention provides a platform fortransporting storage containers between a plurality of verticallyarranged storage grids in a multi-level storage system. The platform isvertically movable along one or more vertical rails arranged outside andfunctionally adjacent to vertically aligned faces of the grid sections.The platform is horizontally adjustable in relation to the one or morevertical rails in an amount sufficient to accommodate a horizontalmisalignment between the rail systems of the respective grid sections.

In one embodiment, wherein the platform is horizontally adjustable inthat it comprises a vertically movable frame member to which isconnected a horizontally movable carriage member. The carriage memberfurther comprises one or more alignment wheels connected to the carriagemember at a position whereby the alignment wheels travel along a surfaceof the vertical rails during vertical movement of the platform. On thevertical rails is arranged one or more alignment brackets. The alignmentbrackets comprise an upper and lower sloped surface and protrude from aside of the vertical rails a distance corresponding to an intendedhorizontal adjustment distance for the platform. In use the alignmentwheels will, during vertical movement of the frame member, contact androll up sloped surface of the protruding alignment bracket mounted onthe vertical rail, thereby causing the carriage member to move in thehorizontal direction in relation to the frame member.

According to yet another aspect, the invention provides a methodtransporting storage containers in an automated storage grid system ofthe type according to the preamble of claim 1. The method according tothis aspect comprises:

a. Arranging a vertically moveable platform adjacent to a face of thegrid,

b. Arranging a dedicated mechanical device for grabbing, lifting andmoving the storage containers from the top of the grid and placingcontainers on the platform and vice versa,

c. Designating a number a cells (P) for the placement of storagecontainers awaiting movement from the grid to the platform, d.Designating a number of cells (G) for the placement of storagecontainers awaiting retrieval by container handling vehicles, e. Causingthe container handling vehicles to place storage containers on cells(P),

f. Causing the dedicated mechanical device to remove any containers fromthe platform and place said containers on cells (G), g. Causing thededicated mechanical device to lift the storage containers from cells(P) and place the containers on the platform, and

h. Causing the platform to lower the containers to a lower level in thegrid system.

The system and method of the invention, at least in the preferredembodiments, can be seen to provide one or more of the followingadvantages:

-   -   It provides a more robust and powerful dedicated lifting and        lowering mechanism for vertically transporting storage        containers than possible by using the lifting mechanisms of the        vehicles. This increases the capacity and through put of the        storage system, and avoids costly wear and tear on the lifting        mechanisms of the vehicles.    -   Alignment of grid levels in a multi-level storage system is not        as critical, since the platform can be adjusted sideways to        account for misalignments.    -   The staging area allows container handling vehicles to drop off        containers and continue on with other tasks, thus avoiding down        time or congestion around a port.    -   Port columns can be rededicated to storage.

BRIEF DESCRIPTION OF THE DRAWINGS

Following drawings are appended to facilitate the understanding of theinvention. The drawings show embodiments of the invention, which willnow be described by way of example only, where:

FIG. 1 is a perspective view of a grid of a prior art automated storageand retrieval system.

FIGS. 2 a and 2 b show a perspective view of a prior art containerhandling vehicle having a centrally arranged cavity for containingstorage containers therein.

FIGS. 3 a and 3 b show a perspective view of a prior art containerhandling vehicle having a cantilever for containing storage containersunderneath.

FIG. 4 is a perspective view of a multi-level automated storage andretrieval system.

FIG. 5 is a side elevational view of a multi-level automated storage andretrieval system.

FIG. 6 a perspective view of a multi-level automated storage andretrieval system with container handling vehicles depicted.

FIG. 7 is a side elevational view of a multi-level automated storage andretrieval system FIG. 8 is a close up view of a motor and pulleyarrangement.

FIG. 9 shows an embodiment of a manipulator trolley for movement ofstorage containers from a top level grid to a lift platform of theinvention.

FIG. 10 shows an embodiment of a manipulator trolley for movement ofstorage containers from a lower level grid to an exemplary lift platformof the invention.

FIG. 11 is a top view of a staging area showing “put” cells and “get”cells.

FIG. 12 is a close up perspective view showing container handlingvehicles placing containers in the staging area.

FIG. 13 is a perspective view of an embodiment of the lift platform.

FIG. 14 is an exploded view of the lift platform of FIG. 13 .

FIG. 15 is a perspective view of the lift platform of FIG. 13 and meansfor adjusting the horizontal position of the platform.

FIG. 16 is a perspective view of an automated storage and retrievalsystem with an offloading/offloading station at a lower level.

FIG. 17 is a close up view of the offloading/onloading station with aconveyor arrangement.

FIG. 18 is a close up view of the offloading/onloading station of FIG.17 with the conveyor arrangement.

FIG. 19 is a close up view of the offloading/onloading station inoperation with autonomous delivery vehicles.

DETAILED DESCRIPTION

In the following, embodiments of the invention will be discussed in moredetail by way of example only and with reference to the appendeddrawings. It should be understood, however, that the drawings are notintended to limit the invention to the subject-matter depicted in thedrawings.

The present invention provides an automated storage and retrieval system1 constructed in accordance with the prior art as described above inconnection with FIGS. 1-3 , i.e., a framework 100 having a number ofupright members 102 and a number of horizontal members 103, which aresupported by the upright members 102 to define a first storage grid 104.The storage grid 104 comprises grid columns 112, a plurality of whichare storage columns 105 in which are stacked storage containers 106.Framework 100 comprises a track system 108 of parallel tracks 110,111extending in an X direction and Y direction arranged across the top ofstorage grid 104, upon which travel a plurality of container handlingvehicles (201/301). The container handling vehicles are preferablyautonomous vehicles arranged to lift storage containers 106 from storagecolumns 105 and transport the storage containers about the grid, as wellas placing storage containers back in the storage columns 105.

In FIG. 1 the storage grid 104 is shown with a height of eight cells. Itis understood, however, that the storage grid 104 in principle can be ofany size. In particular it is understood that storage grid 104 can beconsiderably wider and/or longer and/or deeper than disclosed in FIG. 1. For example, the storage grid 104 may have a horizontal extent of morethan 700×700 grid cells and a depth of more than twelve grid cells.

According to one aspect, automated storage and retrieval system 1 maycomprise multiple levels, as shown in FIGS. 4 and 5 which depict twolevels of storage grids 104 and 104′. There, first storage grid 104 isarranged vertically above a corresponding second storage grid 104′, forexample on an upper floor of a building directly above second storagegrid 104′. FIG. 4 depicts first storage grid 104 and second storage grid104′ as having the same number columns in the X and Y directions. Itshould be understood that this is not necessarily the case, as the gridson different levels may have different configurations. As can be seen inFIG. 5 , grid columns 112 of first storage grid 104 are essentially inalignment with corresponding grid columns 112′ of second storage grid104 along a front face 400 and 400′ respectively. FIG. 6 shows containerhandling vehicles 201 and 201′ (alternatively 301/301′) traveling onrail system 108 and 108′ respectively.

According to one aspect, the present invention provides a bin liftarrangement for transporting storage bins between levels in amulti-level automated storage and retrieval system, and for transportingstorage bins between the top of a storage grid 104/104′ to the bottom ofthe storage grid, where the storage bins can for example be furthertransported to an access station.

The bin lift arrangement comprises a vertically movable platform 402that is vertically movable, adjacent to a face of the grid, along one ormore, preferably two, vertical lift rails 404. As can be seen in FIG. 5, platform 402 has a depth essentially corresponding to the width of astorage container 106, and lift rails 404 are arranged outside a face,for example a front face 400/400′of storage grid 104/104′ in thisembodiment at a distance such that a front edge of platform 402 isfunctionally adjacent to front face 400/400′.

The term “functionally adjacent” as used herein means that the platformcan move up and down in the vicinity of grids 104/104′ withoutinterference. Platform 402 is arranged to receive and transport one ormore storage bins 106 in a vertical direction. Platform 402 may bemovable by a motor and pulley arrangement 406, e.g., as shown in FIG. 8or by other lifting means known in the art.

Storage containers 106 are movable from storage grid 104/104′ to andfrom platform 402 by a dedicated mechanical device for grabbing, liftingand moving the storage containers. The term “dedicated mechanicaldevice” as used herein refers to a device separate from the containerhandling vehicles 201/20G/01/30G, the function of which is primarilyreserved for the movement of containers between the grid and theplatform and vice versa. In one embodiment such a device is in the formof a manipulator trolley 408/408′ as shown in FIGS. 9 and 10 . FIG. 9shows a manipulator trolley 408 arranged in connection with a top levelgrid 104, while FIG. 10 shows a manipulator trolley 408 arranged inconnection with lower level grid 104′. Manipulator trolleys 408/408′have one or more grabbing/lifting mechanisms 410 arranged to grab astorage container 106 from a position at the top of the storage grid andlift the container upward, whereupon the manipulator trolley 408/408′transports the storage container to a position above platform 402,whereupon the grabbing/lifting mechanism 410 lowers the storagecontainer onto the platform. When platform 402 returns with storagecontainers 106, the manipulator trolleys 408/408′ perform this sequencein reverse to remove a container from the platform 402 and place it onthe top of the storage grid 104/104′.

Manipulator trolleys 408/408′ are movable from the position over thestorage grid 104/104′ to the position over platform 402 by travelling bya motorized mechanism along horizontal trolley rails 412. In oneembodiment, shown in FIG. 5 , trolley rails 412 are arranged immediatelyabove rail system 108/108′ on which the container handling vehicles201,301 travel. In another embodiment, shown in FIG. 6 , trolley rails412 may be suspended above rail system 108/108′ at distance greater thanthe height of the vehicles such that the vehicles can travel underneaththe trolley rails 412.

According to one aspect of the invention, as shown in FIG. 11 , the areaof the grid arranged between trolley rails 412 denotes a staging area414. Staging area 414 comprises cells at the top level of the grid wherecontainers 106 may be placed by vehicles 201/301 where they wait to beretrieved and moved by manipulator trolley 408, as well as cells wheremanipulator trolley may place cells where they wait to be retrieved byvehicles. These cells may be referred to as “put” cells and “get” cellsrespectively, represented by the letters P and G in FIG. 11 . Here thereis shown four put cells along the far edge of the grid surface, and fourget cells arranged along the next inner most row, corresponding to aplatform 402 with a capacity of four containers 106. It should beunderstood that platform 402 may have a different capacity, and thatstaging area 414 and the put cells P and get cells G may be arranged inany manner and may be dynamically redesignated as necessary, for exampleaccording to routing considerations determined by the automated storagesystem.

In operation, as illustrated in FIG. 12 , container handling vehicles201,301 place containers 106 in the put cells P, thus freeing thevehicles to attend to other tasks. Manipulator trolley 408/408′ willthen grab the containers 106 in the put cells P, preferably grabbing andlifting the containers 106 in unison, and place the containers 106 onplatform 402. In the event that the platform 402 is transportingcontainers 106 for replacement in the storage columns 112,112′, themanipulator trolley 408 will first place the returning containers in theget cells G, move over to the put cells and lift the containers 106arranged there, and thereafter place those containers on platform 402.Vehicles may then arrive to retrieve the containers 106 from the getcells G, and replace them in the storage columns 112,112′.

According to one embodiment of the invention, platform 402 is movable ina horizontal direction, transverse to its vertical direction of travel.This horizontal movement is provided to account for any potentialhorizontal misalignment between columns 112 of different grid levels.FIGS. 13-15 illustrate one embodiment of

platform 402 that provides for such horizontal displacement. It shouldbe understood that other arrangements for horizontal adjustment ofplatform 402 are possible within the scope of the invention.

FIG. 13 shows an assembled platform 402, while FIG. 14 shows an explodedview of platform 402. Platform 402 comprises a rectangular lifting frame416. Lifting frame 416 has connection points 418 along a top edge, forexample a shackle, for attachment to one or more pulley lines 420operated by motor/pulley arrangement 406. Lifting frame 416 furthercomprises a plurality of rail wheels 422 arranged to engage and travelalong lift rails 404.

Platform 402 further comprises a horizontally movable carriage member424 with a receiving surface 426 on which storage bins 106 may beplaced. Carriage member 424 has rearward extending guide wheels 428mounted on a bracket 430. As seen in FIG. 13 , guide wheels 428 engagean inner surface of horizontal guide rails 432 of lifting frame 416.Guide wheels 428 thus allow carriage member 424 to move horizontally inrelation to lifting frame 416.

As shown in FIG. 15 , lifting frame 416 has essentially the same widthas the space between lift rails 404, with carriage member 424 beingwider than and extending beyond lift rails 404 to both sides. Carriagemember 424 is equipped with one or more alignment wheels 434. Alignmentwheels 434 are mounted in a position on the back portion of carriagemember 424 such that alignment wheels 434 are arranged to the outsidesof lift rails 404.

In the event the columns of a second grid level are out of alignment inthe horizontal direction with a first level by a known distance, analignment bracket 436 may attached to lift rail 404 at the verticalposition where platform 402 will stop to retrieve or unload containers.Alignment bracket 436 has sloped portions 438 and an intermediatestraight portion 440. Sloped portions 438 are arranged to extend thestraight portion 440 a distance from the lift rails 402 a distancecorresponding to the degree of misalignment between columns of the twolevels. As be appreciated from FIG. 15 , as platform 402 is loweredalong lift rails 404, alignment wheels 434 will ride up along slopedportion 438, thereby causing carriage member 424 to move horizontally,via guide wheels 428 in relation to lifting frame 416. According to oneembodiment, the storage and retrieval system may comprise an inventoryof alignment brackets 436 with various offset distances. In the eventthat grid levels become out of alignment, the operator of the system cansimply select the bracket with appropriate offset.

According to yet another embodiment of the invention, anoffloading/offloading station 442 may be arranged at a lower level ofthe automated storage system, at the bottom of lift rails 404. Atoffloading/offloading station 442, storage bins are moved by amanipulator trolley 408 arranged. in connection with station 442 foroffloading storage bins from the lifting arrangement for transport to adifferent location, for example to an access station (not shown) wherethe bins can be accessed by an operator. Conversely, bins may be loadedonto the lift arrangement at station 442 for transporting to an upperlevel of the grid. FIG. 16 shows station 442, with platform 402 at anupper level of the grid for retrieving bins 106, FIG. 17 shows platform402 in transit to station 442, while FIG. 18 shows platform 402 arrivedat station 442. In FIG. 18 , it can be seen that manipulator trolley 408travels along trolley rails 412 to offload/offload bins 106 fromplatform 402.

FIGS. 16-18 show a first embodiment where manipulator trolley 408 movesbins 106 onto, and retrieves bins 106 from a convey system comprising adelivery line 444 and a return line 446. Lines 444 and 446 transportbins 106 to a different location, for example an access station (notshown). In an alternative embodiment, manipulator trolley 408 atoffloading/offloading station 442 may place bins 106 directly into, orretrieve bins 106 directly from, one or more autonomous deliveryvehicles. Delivery vehicles 408 are more fully described in applicationsN020180813 filed Jun. 12, 2018 and N020181005 filed Jul. 19, 2018, theentire contents of which are hereby incorporated by reference as iffully reproduced herein. Delivery vehicles 448 have a bin receivingportion where bins 106 may be placed by manipulator trolley 408.Delivery vehicles 448 are then free to travel along their own dedicatedrail system 450 to a different location, such as the access station. Thecombination of the lifting arrangement of the present invention with theautonomous delivery vehicles may dramatically increase the flexibilityand throughput of the automated storage system. The dedicated railsystem may comprise a first rail system located within the frameworkstructure of the storage grid, and a second rail system located outsidethe framework structure of the storage grid, and wherein the first andsecond rail system are connected such that the delivery vehicle mayoperate between said rail systems.

The second location may be connected to the second rail system.

What is claimed is:
 1. An automated storage system comprising: aplatform for transporting storage containers between a plurality ofvertically arranged storage grids in a multi-level storage system, thegrids of the multi-level storage system being vertically arranged withrespect to each other, each grid of the multi-level storage system beingof a type comprising a plurality of upright members and horizontalmembers defining a framework structure in a form of a grid section ofstorage columns containing storage containers arranged in stacks, andhaving automated container handling vehicles operating on a rail systemon a top level of the grid section, the rail system comprisingperpendicular horizontal tracks upon which the vehicles can travel in afirst direction and a second direction perpendicular to the firstdirection, an intersection of the perpendicular tracks further definingcells above grid columns, wherein the platform is vertically movablealong one or more vertical rails arranged outside and functionallyadjacent to vertically aligned faces of the grid sections, the platformis horizontally adjustable in relation to the one or more vertical railsin an amount sufficient to accommodate a horizontal misalignment betweenthe rail systems of the respective grid sections.
 2. The automatedstorage system according to claim I, wherein the platform furthercomprises a vertically movable frame member to which is connected ahorizontally movable carriage member, the carriage member arranged forreceiving containers, the carriage member being connected to the framemember by one or more guide wheels arranged to roll along one or morehorizontal guide rails of the frame member the carriage member furthercomprising one or more alignment wheels connected to the carriage at aposition relative to vertical rails, whereby the guide wheels arearranged to, during vertical movement of the frame member, contact androll up a sloped surface of a protruding alignment bracket mounted onthe vertical rail, thereby causing the carriage member to move in thehorizontal direction in relation to the frame member.
 3. A method fortransporting storage containers in an automated storage systemcomprising a platform comprising a plurality of upright members andhorizontal members defining a framework structure in a form of a grid ofstorage columns containing storage containers arranged in stacks, andhaving automated container handling vehicles operating on a rail systemon a top level of the grid, the rail system comprising perpendicularhorizontal tracks upon which the vehicles can travel in a firstdirection and a second direction perpendicular to the first direction,an intersection of the perpendicular tracks further defining cells abovegrid columns, the method comprises: arranging a vertically moveableplatform adjacent to a face of the grid; arranging a dedicatedmechanical device for grabbing, lifting and moving the storagecontainers from the top of the grid and placing containers on theplatform and vice versa; designating a number a cells for a placement ofstorage containers awaiting movement from the grid to the platform;designating a number of cells for the placement of storage containersawaiting retrieval by container handling vehicles; causing the containerhandling vehicles to place storage containers on cells; causing thededicated mechanical device to remove any containers from the platformand place said containers on cells; causing the dedicated mechanicaldevice to lift the storage containers from cells and place thecontainers on the platform; and causing the platform to lower thecontainers to a lower level in the grid system.
 4. The method accordingto claim 3, wherein lower level is a vertically arranged lower gridsection, and wherein the platform is horizontally adjustable toaccommodate any horizontal misalignment between the grid section and thelower grid section.
 5. The method according to claim 3, wherein thecells and cells are arranged in respectively rows.
 6. The methodaccording to claim 3, the method further comprises steps of adjusting ahorizontal position of a transportation platform of a type where theplatform travels vertically along one or more vertical rails, whereinthe steps comprises: arranging the platform to be vertically movablealong the vertical rails, wherein the platform comprises a verticallymovable frame member to which is connected to a horizontally movablecarriage member, wherein the carriage member further comprises one ormore alignment guides preferably in a form of wheels connected to thecarriage member at a position whereby the alignment wheels travel alonga surface of the vertical rails during vertical movement of theplatform; arranging, on the vertical rails, one or more alignmentbrackets, the alignment brackets comprising an upper and lower slopedsurface and protruding from a side of the vertical rails a distancecorresponding to an intended horizontal adjustment distance for theplatform; and causing the alignment wheel or wheels to, during verticalmovement of the frame member, contact and roll up sloped surface of theprotruding alignment bracket mounted on the vertical rail, therebycausing the carriage member to move in a horizontal direction inrelation to the frame member.